Three point support brush holder design



Oct. 30, 1956 F. M. POTTER THREE POINT SUPPORT BRUSH HOLDER DESIGN Filed Sept. 22, 1955 FIG. 1

FIG. 2

//VV/VrO Q FREDER/CK M. 1 07 7 15 P United States Patent THREE POINT SUPPGRT BRUSH HOLDER DESIGN Frederick M. Potter, Westwood, N. J., assignor to Bendix Aviation Corporation, Teterboro, N. 3., a corporation of Delaware Application September 22, 1953, Serial No. 381,674

4 Claims. (Cl. 310-239) The present invention relates to 'dynamoelectric machines and more particularly to brush holders for dynamoelectric machines.

It is desirable to keep a brush as stable as possible in the brush holder for the best operation of dynamoelectric machines. It is recognized that the support of the brush as provided by the brush holder is of paramount importance. The ideal support would probably be a perfectly flat back, however, in practice this is rather a remote possibility.

The present invention provides a novel brush supporting means which provides basically three points of support. Two points of support are close to the commutator and close to the edge of the brush and the other supporting point is at the top center of the brush.

it is an object of the invention to provide an improved brush holder for a dynamoelectric machine.

Another object of the invention is to provide a brush holder having three points of support.

Another object of the invention is to provide a tripod support for a brush in the brush holder.

The above and other objects and features of the invention will appear more fully hereinafter from a consideration of the following description, taken in connection with the accompanying drawing, wherein one embodiment of the invention is illustrated by way of example.

In the drawing:

The Figure l is a partial cutaway section of a brush holder illustrating one embodiment of the invention.

Figure 2 is a partial cutaway section of a brush holder illustrating another embodiment of the invention.

In the drawing, a brush holder is indicated in Figure 1 generally by the numeral 1 and comprises in general of a back plate 2 mounted on a supporting arm 3. The arm 3 has a shank portion 4 and threaded portion 5 for mounting in a dynamoelectric machine (not shown).

Arm 6 extending from the plate 2 is adapted to hold a spring 7, which applies pressure to brush 8. The brush 8 may be connected electrically by any conventional means (not shown).

A novel feature of the present invention is the provision of the supporting strips 9 and 10. The strip 9 has a taper that progresses outwardly to a point 11. The Strip 10 has a taper that progresses outwardly to a point 12. It can be seen that the brush will contact the supporting strips at the points 11 and 12. A rod 13 serves to hold the brush against the strips 9 and 10.

Referring now to Figure 2, wherein a further embodiment of the invention is illustrated, a brush holder 20 has a back plate 21 adapted to be mounted on a supporting arm (not shown) in a conventional manner. EX- tending from the plate 21 are arms 22 for supporting springs 23 to apply pressure to brush 24. The arms 22 also serve to hold rod 25 which holds the brushes 24 against the plate 21.

The plate 21 has cutout sections 26 adjacent the lower edge thereof and forming legs 27 on either side. The brushes 24 have cutout portions 28 on the upper part on the side adjacent the plate 21. A rib 29 is formed by the cutout portions 28.

The operation is somewhat similar to that as described for Figure 1. The rib 29 coacting with the plate 21 forms one point of support and the legs 27 on either side of the cutout portion 26 form the other two points of support.

While the portion 26 has been illustrated as being cutout, it is understood that it could be a depressed section in the plate 21.

In operation, the brush rests against the three points, that is, two points 11 and the point 10 and provides three points of support, just as the three-legged milking stool provides a stable support. The points 11 are important, as they serve to keep the brush from vibrating or oscillating at the contacting surface. This arrangement permits the use of brushes having uneven surfaces.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangement of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention.

What is claimed is:

1. Brush rigging for use in a dynamoelectric machine, comprising a back support, side supports and a front support, said back support having a raised portion adjacent the top and center thereof and raised portions on both sides adjacent the bottom thereof to provide a three point support.

2. A brush assembly comprising a brush, a supporting plate having raised portions adjacent both sides and tapered progressively outward towards the bottom of said plate, a raised portion adjacent the center of said plate and tapered progressively outward toward the top of said plate, and means for holding said brush into engagement with said raised portions.

3. A brush assembly comprising a plurality of brushes, a compartment for each of said brushes, one side of said compartments forming a supporting plate for said brushes, and means for supporting said brushes adjacent the bottom edges and adjacent the top center to provide a three point support for said brushes.

4. A brush assembly comprising a brush, a compartment for said brush, one wall of said compartment forming a supporting plate for said brush, a cutout section in the lower half of said supporting plate forming legs on either side thereof, said brush having the side adjacent to said supporting plate relieved to form a center ridge on said brush, said legs and said ridge forming a three point support for said brush.

References Cited in the tile of this patent UNITED STATES PATENTS 462,883 Short Nov. 10, l89l 840,506 Misland Jan. 8, 1907 2,428,250 Thomas Sept. 30, 1947 2,607,817 Peterlik Aug. 19, 1952 FOREIGN PATENTS 124,649 Germany Oct. 19, 1901 432,972 Great Britain Aug. 7, 1935 521,285 Germany Mar. 21, 1931 

